perms — Return all permutations of a vector as rows.

P = perms(v) returns every permutation of the elements in vector v, one permutation per row. RunMat follows MATLAB's reverse lexicographic row order and preserves supported vector container classes.

Syntax

P = perms(v)

Inputs

Returns

Errors

How perms works

• perms(v) accepts row vectors, column vectors, scalars, and empty vectors.
• The output has factorial(numel(v)) rows and numel(v) columns.
• Rows are emitted in MATLAB-compatible reverse lexicographic permutation order relative to the original element positions.
• Duplicate input values are permuted by position and are not deduplicated.
• Dense numeric tensors preserve their RunMat dtype metadata; logical, character, string-array, and cell-array vectors return matching container types.
• Scalar numeric, logical, and string inputs return the scalar value unchanged.
• Complex numeric vectors are permuted positionally and preserve their complex values.
• Inputs that are not vectors, unsupported object-like values, sparse tensors, and outputs beyond RunMat's materialization limit raise stable errors.

Examples

Permute a numeric vector

P = perms([1 2 3])

Expected output:

P =
     3     2     1
     3     1     2
     2     3     1
     2     1     3
     1     3     2
     1     2     3

Permute characters

P = perms('abc')

Expected output:

P =
    'cba'
    'cab'
    'bca'
    'bac'
    'acb'
    'abc'

Duplicate values are retained

P = perms([1 1 2])

Expected output:

% P has six rows; duplicate rows are preserved.

Work with an empty vector

P = perms([])

Expected output:

% P is a 1-by-0 empty double array.

Using perms with coding agents

Open a RunMat example with live inputs, then ask the agent to explain how perms changes the result.

FAQ

Related Array functions

Open-source implementation

Unlike proprietary runtimes, every RunMat function is open-source. Read exactly how perms is executed, line by line, in Rust.

• View the source for perms in Rust on GitHub
• Learn how the RunMat runtime works
• Found a bug? Open an issue with a minimal reproduction.

About RunMat

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